X-ray imaging of bio-matter @ synchrotrons & lab sources Janos - PowerPoint PPT Presentation

X-ray imaging of bio-matter @ synchrotrons & lab sources Janos Kirz EuXFEL 11/2017

Origins • W. C. Röntgen 1895 – Nov 8 – first observation – Nov 9 – Dec 27 experimentation, write-up – Dec 28 – manuscript submitted • Sitzungsberichte der Physikalischen-medizinischen Gesellschaft zu Würzburg • See bones in hand – shadowgraphs Instant sensation around the world Radiology – absorption contrast Works well for bone fracture air vs fluid in lung tooth decay

3D Imaging: CAT scans • 3D imaging based on many projections • 1979 Nobel prize Godfrey Hounsfield & Allan McLeod Cormack • Resolution: several mm • Limitations: breathing, beating heart, digestion,…

Better radiology ? • Hundreds of images: high radiation dose! • Absorption contrast in soft tissue poor • To reduce dose – improve contrast! • Extract phase shift from interference pattern – Bonse-Hart interferometer • Appl. Phys. Lett 6 , 155 (1965) – Phase contrast tomography • A. Momose et al. – Nature Med. 2 , 473 (1996)

Interferometry without crystals • Grating-based phase measurement – – Using Talbot (1836) effect (self-image) • A. Momose et al. Jpn. J Appl. Phy. 42 , L866 (2003) • Spring-8 source for coherence • Object distorts Moire pattern • Talbot-Lau interferometer • Third grating for use with ordinary X-ray tube – F. Pfeiffer et al. Nature Phys. 2 , 258 (2006) • Intensive development worldwide

Absorption & Phase contrast F. Pfeiffer et al. Nature Phys. 2 , 258 (2006)

Application to mammography Phase contrast Absorption contrast (From Konica – Minolta)

X-ray micro-Tomography-ALS 8.3.2 Lots of Math

Microtomography • Simple projection onto detector Resolution: ~ 1-5 µm • Commercial “microscopes” • Lab sources or synchrotrons – Zeiss (formerly XRADIA) – Brucker (formerly Skyscan) • 3D Studies of bone structure, seeds, small animals

Examples of Grapevine Xylem

Get insights in insect flight control Investigate the biomechanics underlying flight manoeuvres and gaze shifts à CT following the dynamics of 100+ Hz wing beat! Need: • single-shot propagation-based phase contrast • high-speed X-ray tomographic microscopy Requires: Coherence and Flux SLS beam BRIGHTNESS So, this is a perfect task for a synchrotron! S. M. Walker et al. P{LOS Biology 12, e1001823 (2014) 11

Toward higher resolution • Microscopes with zone plate optics – Resolution ~ 20 nm (50 nm in 3D) • Radiation damage becomes limitation! • Cryo preserves morphology • Instruments at – BESSY II – ALS – ALBA – …

Cryo Soft X-ray Tomography of Cells at the MISTRAL beamline E. Pereiro et al. J. Synchr. Rad. 16 , 505-512 (2009) reconstructed slice 1 µm A. SorrenBno et al. J. Synchr. Rad. 22 , 1112-1117 (2015)

The ultimate challenge Radiation damage in biological samples Frozen hydrated state of protein Howells et al. JESRP 170, 4 (2009) Resolution limit ? Inverse fourth power law of dose vs resolution: Dose ~ 1/resolution-size 4

Scanning X-ray diffracBon microscopy Ptychography with a focused X-ray probe J. Rodenburg Pilatus 2M Reconstruct bith amplitude and phase P. Thibault, M. Dierolf, A. Menzel, O. Bunk, C. David, F. Pfeiffer, Science, 321 , 379-382 (2008). 15

Frozen hydrated unstained brain tissue Locate, extract and further study intact hallmarks of Parkinson disease Sarah Shamoradian Large volumes High resoluBon As close to naBve state as possible (no staining) Quickly biopsy-punched, infiltrated with cryo protectant, mounted on pin and gradually frozen Trimmed with cryo ultramicrotome Cryo transferred to OMNY ~ 80 micron at the base, ~ 100 nm 3D resoluBon 446 projecBons 17 hour measurement Shamoradian et al., Sci. Rep. 6291 (2017) Page 16

3D Elemental mapping by XRF • 3D scan as for tomography • Record fluorescence spectrum for each point • Perform tomographic recontstruction for each element

3D elemental microtomography of Cyclotella meneghiana M. de Jonge, et al., PNAS 107, 15676, (2010)

Changing Landscape of X-ray facilities • ~ 1985- dedicated storage rings – 30+ years: a revolution in X-ray analysis • ~ 2010 Toward higher brightness, coherence – MBA lattice , MAX IV, Sirius, storage ring upgrades – FEL s LCLS, FLASH, FERMI, SACLA, EuXFEL,… • Older sources: DORIS, NSLS, Daresbury,… shut down – Fewer stations available for routine measurements

New initiatives in Lab-scale sources – to fill the gap • EXCILLUM – liquid metal jet • Lyncean – back-scattered Compton • Sigray – microstructured anode in diamond substrate

Conclusions I • X-rays are great! – Penetrate opaque objects – Rich spectra allow elemental & chemical info • Radiation damage is a concern • One way to mitigate radiation damage: cryo • Other ways: • many copies, as in crystals • or diffract & destroy • ... but ptychography not compatible

Conclusions II • A bit of humility: • There is competition! – MRI for imaging humans – Cryo EM for high resolution on thin samples – Super resolution visible light microscopy

Acknowledgments • Thanks to colleages who provided material for this talk: – Manuel Guizar Sicarios – Eva Pereiro – Marco Stampanoni – Andrew McElrone

Thank you